US 6,661,509 B2 · Method and apparatus for alignment of multiple beam paths in spectroscopy

Abstract

Alignment of multiple beam paths in a microscope such as a Raman spectrographic microscope utilizes an alignment instrument that is mounted on the stage of the microscope and positioned by the operator until an aperture of the alignment instrument is at an intended focal point of the microscope. A light source within the alignment instrument is turned on to project light through the aperture which is passed on a return light beam path to the input aperture of a spectrograph where it is detected. Features are included in the return beam path to adjust the beam path until the light detected is maximized, thereby aligning the return beam path to the intended focal point. The light source in the alignment instrument is turned off and a light source in the microscope system, such as a laser, is activated to provide an illumination light beam on a beam path that extends through the objective lens of the microscope, which focuses the beam onto the alignment instrument. The illumination beam that passes through the aperture is detected by a detector within the alignment instrument. The illumination beam path is then adjusted until the detected light is maximized, thereby aligning the illumination beam path to the intended focal point.

Claims14

Dependent claims

A method for aligning beam paths in a microscope system having an illumination light beam path from a source to an objective lens of the microscope, the illumination light beam being focussed by the objective lens at a focal point in a sample position at which a sample may be located, a scattering light return beam path for scattering light collected from the sample position by the objective lens that extends to a light detector, and a visible light microscope beam path from the sample position through the objective lens to form an image of the sample position which may be observed by a viewer directly or with use of a video camera, comprising the steps of:

(a) positioning a spatially limited entrance aperture in the sample position at an intended focal point of the objective lens;
(b) passing illuminating light from the source on the illuminating beam path through the objective lens toward the entrance aperture positioned at the intended focal point and detecting the light passed through the entrance aperture, and adjusting the illumination beam path until the detected light is maximized;
(c) positioning a spatially limited exit aperture in the sample position at the intended focal point of the objective lens;
and
(d) projecting light through the exit aperture located at the intended focal point into the objective lens and passing the light on the return beam path to the light detector and detecting the light by the detector, and adjusting the return beam path until the output of the light detector is maximized.

2 more elements

A Raman spectrographic microscope system comprising:

(a) optical elements including an objective lens defining a microscope optical beam path for light from a sample position at which a sample may be located collected by the objective lens that extends to an image position at which an image of the sample position may be observed;
(b) optical elements defining an illuminating beam path from an illuminating light source to the objective lens, the objective lens focusing the illuminating beam to a focal point in the sample position;
(c) a spectrograph including an input aperture and a detector for detecting light entering the input aperture o#the spectrograph;
(d) optical elements including the objective lens defining a Raman scattered light return beam path from the objective lens to the input aperture of the spectrograph;
(e) means interposed in the illumination beam path for selectively displacing the illumination beam from an axis of the beam;
(f) means interposed in the Raman scattered light return beam path for displacing the beam from an axis of the beam;
and
(g) an alignment instrument mountable on a stage of the microscope system in the sample position and having a face plate with a spatially limited aperture therein which can be positioned at the focal point of the objective lens, the alignment instrument selectively activatable to provide light out through the aperture on the return beam path to the spectrograph and also selectively activatable to receive light through the aperture from the illumination light beam path and to detect the intensity of the light passed through the aperture.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for alignment of multiple beam paths in spectroscopy

Life of this patent

Method and apparatus for alignment of multiple beam paths in spectroscopy

Life of this patent

Abstract

Claims14